The denominational value or identity of banknotes and many other types of documents can be readily discerned by persons whose eyesight is not impaired but for persons who are blind it is necessary to use other means, such as a portable reader designed for the particular document in question, to determine such information. A printed braille section placed on such a document could provide a means for such identification and, advantageously, would be integral to the document and avoid the need for an auxiliary reading device. However, the broad circulation and public handling of documents such as banknotes subjects them to substantial wear and any braille printing applied to such documents in the normal manner of embossed printing would not be sufficiently durable because the embossments would soon be compressed and become non-tactile.
Consequently, there is a need in the industry for a means of providing to security documents, banknotes, etc. durable (i.e. relatively permanent) tactile identifying indicia which are able to withstand the substantial wear caused by public circulation and handling and can be readily used by persons with impaired eyesight to determine the denomination or identification of such document.